DE3727182A1 - PRODUCTION AND PROCESSING OF MIXTURES WITH A HIGH CONTENT OF ORGANOCYCLOSILOXANES - Google Patents

Description

The invention relates to the production and further processing processing of mixtures with a high proportion of organocyclosi loxanes, these mixtures having a low content of Hydroxyl groups bonded directly to silicon atoms sen.

When representing linear polydiorganosiloxanes for example, diorganodihalosilane is formed as a secondary Products organocyclosiloxanes, which from the reaction mixture can be removed by distillation. This organocyclosi Distillate containing loxanes can in principle be combined with others Silanes or siloxanes equilibrated and / or condensed are and thus z. B. as a basis for the production of Serve silicones with reactive groups.

When implementing such distillates with reactive groups bearing silanes showed that the products of this order Settlements with regard to their viscosities depending on the quality of the distillates used fluctuated greatly. That was dar due to the fact that the distillates mentioned in addition to Orga nocyclosiloxanes also in short-chain in varying amounts contain linear organosiloxanes, which are in the terminal Units of hydroxyl groups directly attached to silicon atoms exhibit.

The object of the present invention was to organize organocyclosi To provide mixtures containing loxanes, which are known as Starting materials for silicones with reproducible viscosity own. Furthermore, it was the task of the present inventor dung, a process for the production of functional groups to provide carrying organopolysiloxanes. The The above tasks are accomplished by the present Invention solved by a method for the production of Mixtures containing organocyclosiloxanes, which are suitable are net as starting materials for the production of silicones controlled viscosity, characterized in that one that in the manufacture of linear organopolysiloxanes as Distillate from the product mixture Organocyclosiloxanes and an alternating proportion of short chain linear organosiloxanes with condensation catalysts gate (s) treated, or the mixture thus obtainable with min at least one organosilane carrying functional groups or siloxane, each with at least one condensation capable group.

The as starting material for the process according to the invention using mixture of organocyclosiloxanes and short chain term linear organosiloxanes are preferably those of formula

wherein

R are identical or different, optionally substituted hydrocarbon radicals having 1 to 18 carbon atoms or hydroxyl groups and
n is an integer from 0 to 3 and an average from 1.9 to 2.1

mean.

In particular, it exists as a starting material for inventions Mixture to be used according to the invention mainly from organocyclosiloxanes of the formula

(R₂SiO) _x (II),

where x can have a value from 3 to 20, and short-chain linear organosiloxanes of the formula

HO- (R₂SiO) _y -H (III),

where y can assume values from 1 to 20 and in the above formulas (II) and (III) R has the same meanings as in formula (I). Examples of radicals R are alkyl radicals, such as the methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl , neo-pentyl, tert-pentyl, hexyl, such as the n-hexyl, heptyl, such as the n-heptyl, octyl, such as the n-octyl and iso-octyl, such as the 2,2,4-trimethylpentyl, Nonyl radicals, such as the n-nonyl radical, decyl radicals, such as the n-decyl radical, dodecyl radicals, such as the n-dodecyl radical, octadecyl radicals, such as the n-octadecyl radical; Alkenyl groups such as the vinyl and allyl groups; Cycloalkyl radicals, such as cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl radicals; Aryl radicals, such as the phenyl, naphthyl and anthryl and phenanthryl radical; Alkaryl groups such as o-, m-, p-tolyl groups, xylyl groups and ethylphenyl groups; Aralkyl radicals, such as the benzyl radical, the alpha- and the β- phenylethyl radical; Examples of substituted radicals R are cyanoalkyl radicals, such as the b- cyanoethyl radical, and halogenated hydrocarbon radicals, for example haloalkyl radicals, such as the 3,3,3-tri fluoro-n-propyl radical, the 2,2,2,2 ′, 2 ′, 2'-hexafluoroisopropyl radical, the heptafluoroisopropyl radical, and haloaryl radicals, such as the o-, m- and p-chlorophenyl radical. The radicals R are preferably C₁ to C₃-alkyl, phenyl and / or vinyl radicals.

It is particularly preferred that at least 80% is preferred as at least 90% of the radicals R are methyl radicals.

The as starting material for the process according to the invention using mixture, which in particular organocyclo siloxanes of the formula (II) and short-chain linear siloxanes of the formula (III) is, as already mentioned, in a first process with condensation catalyst (s) treated. Examples of such condensation catalysts are primarily substances according to the definition of Brönstedt or Lewis to be referred to as acids or bases are. These are heterogeneous catalysts, such as acid activated bleaching earths and zeolites and homogeneous catalyst ren. Examples of homogeneous acidic catalysts are proton acids such as sulfuric acid, chlorosulfonic acid, selenic acid, Nitric acid, phosphoric acids, boric acid, Lewis acids such as Iron (III) chloride, iron (III) chloride hexahydrate, Aluminum chloride, boron trifluoride, zinc chloride, tin (IV) - chloride, phosphorus nitride chlorides or their implementation pro products with organosilanes and / or siloxanes, aluminum sul fat, or mixtures of at least two of these substances. Examples of basic catalysts are alkali metal hydroxides,  especially potassium and cesium hydroxide, alkali silanolates, Alkaline alcoholates, quaternary ammonium hydroxides such as tetrams thylammonium hydroxide, benzyltrimethylammonium hydroxide, beta Hydroxyethyltrimethylammonium 2-ethylhexoate, quaternary Phosphonium hydroxides such as tetra-n-butylphosphonium hydroxide and tri-n-butyl-3- [tris (trimethylsiloxy) silyl] -n-propyl phosphonium hydroxide, potassium amide, amines and amine mixtures and mixtures of at least two of the as basic Kataly called substances or classes of substances.

Depending on the choice of substances serving as catalysts the amounts to be used differ.

In the process according to the invention, acidic catalysts are in particular phosphorus nitride chlorides and their implementation products with organosilanes and / or -siloxanes preferred.

The dosing of the condensation catalyst, the reaction temperature and reaction time are to be chosen so that the whole predominant condensation, in particular from the terminal silanol groups of the compounds of the formula (III), and only as small a part as possible brierung, for example u. a. Cleavage of the siloxane bindings of the organocyclosiloxanes occurs.

If phosphorus nitride chlorides are used, then The inventive method preferably 1 ppm by weight to 1000 ppm by weight, in particular 5 ppm by weight 100 Weight ppm of phosphorus nitride chlorides, in each case based on the total weight of the organocyclosiloxanes to be treated containing mixture used. Are used as catalysts Reaction products of phosphorus nitride chlorides with organo silanes or organosiloxanes used, so is accordingly use more catalyst.  

Temperatures from 0 ° C to 150 ° C, especially from 10 ° C to 50 ° C and reaction times from 5 min to 48 h, ins particularly preferred from 15 min to 5 h.

The treatment according to the invention with condensation catalyst r (en) can increase compared to normal pressure (0.1 MPa (abs.)) tem or reduced pressure can be performed. Press from 0.09 MPa (abs.) To 0.11 MPa (abs.) Are preferred.

The condensation catalysts are preferably after Treatment deactivated if the mixture treated in this way should be stored for a long time. Under Deactivate is in this regard in particular the removal from the Mixing, for example by filtration, if appropriate after previous adsorption or absorption on solids, and chemical inerting, for example through new understanding. The type of deactivation can vary according to the later use for phosphorus nitride chlorine by neutralization with or adsorption or absorption on an (with subsequent filtration) tertiary amines, n- Butyllithium, lithium hydroxide, lithium carbonate, sodium car bonate, sodium bicarbonate, potassium carbonate or potassium hydrogen carbonate, using solid oxides, hydroxides or car bonate of divalent or trivalent metals, such as Mg, Ca, Sr, Ba, Zn, Al as well as by basic ion exchangers. The treated according to the inventive method and preferably of active condensation catalyst largely exempted mixtures generally have no more than 0.1% of Si-bonded hydroxyl groups (determined according to Zere witinoff).

The mixtures obtained in this way can be used for the production of all polyorganosiloxanes which have hitherto been able to be produced using organocyclosiloxanes. Examples of such polyorganosiloxanes are α, ω- bis trimethylsiloxypolydimethylsiloxanes; α, ω -dihydroxypolydi methylsiloxanes; α, ω- Dialkoxypolydimethylsiloxane and, especially functional group-bearing polyorganosiloxanes. Suitable functional groups are in particular Si-C-bonded amino and / or mercapto residues and / or groups bearing epoxy functions, vinyl and allyl residues, Si-C-bonded ethers and polyethers, acids, lactones, lactams and the like.

Preferred examples of such groups are the vinyl, beta-aminoethyl-gamma-aminopropyl-, gamma-aminopropyl-, gamma- (cyclohexylamino) propyl, N-morpholinopropyl, Glycidoxypropyl, mercaptopropyl and methacryloxypropyl groups.

Organopolysiloxanes carrying these functional groups can NEN can be prepared by using the above method treated mixtures containing organocyclosiloxanes, with at least one organo carrying functional groups converts silane or siloxane, the organosilane or -siloxane each have at least one condensable group owns. Examples of such condensable groups are alkoxy groups like the methoxy and ethoxy groups, Halogen residues, especially Si-bonded chlorine atoms and Acyloxy residues, such as the acetoxy residue. Are preferred because their easier accessibility methoxy, ethoxy, Methoxyethoxy, acetoxy and chlorine residues.

The mixtures treated according to the invention are preferred wise with silanes of the formula

R _q R ′ _r SiX _{(4- qr)} (IV)

or reacted with partial hydrolyzates of such silanes, wherein in Formula (IV) above

R has the meaning given for the formula (I),
R 'mean the same or different Si-C-bonded radicals, which are composed of hydrogen, up to 10 carbon atoms and optionally nitrogen, oxygen and / or sulfur atoms;
X same or different condensable groups, preferably methoxy, ethoxy, methoxyethoxy, acetoxy or chlorine groups;
q is an integer of 0, 1 or 2;
r is an integer of 1, 2 or 3 and the sum of q and r is a maximum of 3.

The sum of q and r is preferably at most 2.

Particularly preferred examples of silanes of the formula (IV) are vinyltrichlorosilane, vinyltrimethoxysilane, vinyltri ethoxysilane, vinyl tris (methoxyethoxy) silane, vinyl triacetoxy silane, beta-aminoethyl-gamma-aminopropyltrimethoxysilane, beta-aminoethyl-gamma-aminopropyltriethoxysilane, beta-amino ethyl-gamma-aminopropylmethyldimethoxysilane, gamma-aminopro pyltriethoxysilane, gamma-aminopropyltrimethoxysilane, gamma (Cyclohexylamino) propyltriethoxysilane, gamma (cyclohexyl amino) propyltrimethoxysilane, gamma-N-morpholinopropyltri methoxysilane, methacryloxypropyl (trimethoxysilane), mercapto propyltrimethoxysilane, 3- (triethoxysilylpropyl) amber acid anhydride, methacryloxypropyltri (methoxyethoxy) silane, Mercaptopropyltri (methoxyethoxy) silane, vinylmethyldi methoxysilane, mercaptopropylmethyldimethoxysilane, methacrylic  oxypropylmethyldimethoxysilane, glycidoxypropyltriethoxysilane and the like.

The inventive method for the production of functional group-bearing polyorganosiloxanes preferably at temperatures from 0 ° C to 250 ° C, especially from 50 ° C to 180 ° C.

Pressures from 0.09 to 0.11 MPa (abs.) Are preferred.

The process can be carried out in the presence of an inert solvent be performed. The reaction preferably contains mixture less than 1%, especially less than 1 ‰ based on their weight of solvent.

Preferably the reaction is carried out in the presence of a Condensation and equilibration accelerating catalysis tors performed.

Examples of such catalysts are already available as Examples of condensation catalysts listed.

Becomes an amino functional in the inventive method Silane of formula (IV) used, which is particularly preferred is as a condensation and equilibration catalyst toren basic catalysts, especially tertiary Ammonium hydroxides preferred.

The organocyclosi treated as described above Mixtures containing loxanes are, as in the shown below, the relatively more expensive pure organocyclosiloxanes as starting materials for Production of functional groups Equal to organopolysiloxanes.

In the examples below, all amounts refer to unless otherwise stated, gave weight. Like this as far as no temperatures or pressures are given worked at 25 ° C or 0.1 MPa (abs.). The determination of Si-bound hydroxyl groups took place after the Zerewitinoff's method.

example 1

To 1000 g of a mixture containing organocyclosiloxanes containing 0.26% by weight of Si-bonded Hydroxyl groups became 0.08 ml of a 25% by weight solution of phosphorus nitride chloride (30 ppm) in dichloromethane and left for 1 h at 25 ° C. The mixture that has become cloudy was mixed with 25 g of NaHCO₃, with 25 g of anhydrous Na₂SO₄ dried and filtered. The content was in the filtrate Hydroxyl groups below 0.1% by weight.

Example 2

To 700 g of a mixture containing organocyclosiloxanes with a content of Si-bonded hydroxyl groups of 0.26% by weight were 0.056 ml of a 25 wt .-% solution of Phosphorni trid chloride (30 ppm) in dichloromethane, stirred briefly and allowed to stand at 25 ° C for 8 hours. Then 14 g NaHCO₃ added, stirred for one hour and then fil trated. 7.8 g of N- (2-aminoethyl) - were added to 600 g of the filtrate. 3-aminopropyl-methyldimethoxysilane and 0.3 ml of a 40% by weight methanolic solution of benzyltrimethylammonium added hydroxide, stirred at 80 ° C for 1 h and then 2 h long at 150 ° C and 2 kPa (abs.) nitrogen through the solution headed. 525 g of a clear, color loose oil with a viscosity of 1156 mPa.s at 25 ° C and an amine number of 0.14. (The amine number corresponds to Ver need 1 N HCl in ml per g of sample weight for the titration  against tetrabromophthalein.)

Comparative Example 1

Example 2 was repeated with the modification that none Phosphorus nitride chloride was added. 520 g were obtained a clear colorless oil with a viscosity of 62,400 mPa.s at 25 ° C and an amine number of 0.14.

Example 3

Use 700 g of one of those in the previous examples ver in their content of Si-bonded hydroxyl groups different mixture containing organocyclosiloxanes treated as indicated in Example 2. 520 g were obtained a clear, colorless oil with a viscosity of 1038 mPa.s at 25 ° C.

Comparative Example 2

Example 3 was repeated with the modification that none Phosphorus nitride chloride was added. 515 g were obtained a clear, colorless oil with a viscosity of 12,000 mPa.s at 25 ° C.

Comparative Example 3

Example 2 was repeated with the modification that instead 600 g of the filtrate with phosphorus nitride chloride and Sodium bicarbonate treated solution 600 g octamethyl cyclotetrasiloxane was used. 532 g were obtained a clear, colorless oil with a viscosity of 946 mPa.s at 25 ° C.

Claims (7)

1. A process for the preparation of mixtures containing organocyclosiloxanes which are suitable as starting materials for the production of silicones of controlled viscosity, characterized in that the mixture of organocyclosiloxanes and a changing proportion of short-chain linear ones which is obtained in the production of linear organopolysiloxanes as a distillate from the product mixture Organosiloxanes treated with condensation catalyst (s). 2. The method according to claim 1, characterized in that the condensation catalyst (s) subsequently deactivated or removed from said mixture will. 3. The method according to claim 1 or 2, characterized characterized in that the directly attached to a silicon atom bound organic groups of the organocyclosiloxanes and short chain linear organosiloxanes at least 80% based on their number of methyl groups. 4. The method according to claim 1, 2 or 3, characterized characterized in that as condensation catalyst (s) Phosphorus nitride chlorides are used. 5. Process for the production of functional groups Polyorganosiloxanes, characterized in that the according to the method of claim 1, 2, 3 or 4 available mixture with at least one functional Organosilane or siloxane bearing groups, each with implements at least one condensable group.   6. The method according to claim 5, characterized in that the organosilane or siloxane used is a silane of the formula R _q R ' _r SiX _{(4- qr)} (IV) or an organosiloxane available as a partial hydrolyzate of such an organosilane, wherein in the above Formula the radicals R have the meaning given in claim 1,
R 'are identical or different, Si-C-bonded radicals which are composed of hydrogen, up to 10 carbon atoms and optionally nitrogen, oxygen and / or sulfur atoms;
X same or different condensable groups, preferably methoxy, ethoxy, methoxyethoxy, acetoxy or chlorine groups;
q is an integer of 0, 1 or 2;
r is an integer of 1, 2 or 3 and the sum of q and r is a maximum of 3. 7. The method according to claim 5 or 6, characterized characterized in that as an organosilane or siloxane amino-functional organosilane or siloxane used becomes.